Here's some (longish) history on the project, so that folks can see where I'm coming from and what I'm trying to figure out...
Goals...
This is my second home with solar PV. I'm using the same installer, who did a great job on the first home, both in workmanship and quality of products. I was very pleased with the install and ran the system for 7-8 years, before selling the house. With this house, I was looking to do two things different (of which I'd have the installer provide)...
1) Generator
I wanted an automatic whole house generator for backup power. Our previous home would loose power a few times each Winter, mostly for a few hours, but occasionally a few days have occurred over the years. With our current home (in the same rural town, but at the end of the line for utility company lines), we are expecting (and have heard from neighbors) that outages are more common.
Given we are older, and my wife can't haul around 5 gallon containers of gasoline, I wanted to have a propane generator with automatic switchover. We also wanted whole house, instead of critical circuits, mostly because of convenience (years after we had our previous generator, we discovered we needed other/more circuits covered - could have done some rewiring, obviously, but it was a pain having to run extension cords to keep a UPS running in the study, or power a CPAP machine in a bedroom).
2) Battery
I wanted to consider battery backup, mostly as a long term cost savings measure, given that propane is expensive here. The thought was that for most outages, the battery would handle things (and save on fuel), but we'd still have the generator for those extreme outages.
Design...
We used the same installer, as were happy with the work they did before, and they are familiar with our previous system, power consumption, etc.
The designed system was 11.9 Kw of panels (up from 8.55 kW at previous home) with a SolarEdge 7.6 kW inverter (just like our previous home). They would use the "new" Energy Hub and Backup Interface that SolarEdge provided, which has support for EV charges, batteries, multiple inverters, etc. They had the option of the 10 kWh LG battery or the 16 kWh LG that was just becoming available.
Given the hub could support only up to two batteries and the difference in price between the two, we decided to go with the 16 kWh battery. As I understood it, the batteries are charged without using the inverter, so excess power from the panels can charge the batteries without affecting the power that the inverter can provide.
They had spec'ed out a Generac 10 kWh propane generator for the project as well. I asked about the size of the generator (as people I know have 15-20 kWh ones, although with much larger houses), and was told that they way the system would work is that, when the grid fails, the house would be powered by battery (and PV, if available). When the battery gets low, the generator would be used to "recharge" the battery. I was convinced that was fine.
It was more costly than we had expected for system cost, but this was to be our retirement home and we figured we'd splurge a bit and try to get something setup that would work for us, allow grown in the future (say with EV cars), and save us money operationally down the road.
Project...
Here's were things went awry...
The PV (only) system was installed in July of last year. The battery was on back-order due to newness and supply chain issues. The generator came in and was installed in November, and the installer connected in up to the backup interface. Without a battery, though, this did not work, and it was around that time that we (both the installer and I) discovered that although SolarEdge's data sheet said their inverter/hub/backup interface worked with a generator (and the reason why the installer went with that solution), but had a asterisk and in fine print said "with a required firmware update".
It turns out that the firmware was NOT available, and over time we kept getting different dates of availability Q4 2021, then Q4 2022. The installer, put in a sub panel with ATS and critical circuits routed to it, and connected the generator to that. At least through the Winter of 2021, we had a generator for power outages.
In August of this year, the battery finally came in, and was installed. Now, when the PV stops producing, the battery powers the house (another painful story - as it only draws down to 80% capacity and then stops - I've been nagging my installer and SolarEdge on how to get that so it draws down to 20%). When the power goes out, the generator comes on, and powers critical circuits.
Current Status...
So, I have all the pieces, but not integrated in. Well, I just found out from SolarEdge that the firmware is available. They had a release note dated in July (I've been nagging them every month asking about the firmware and it wasn't until now that I found out). I'm trying to get a date from my installer, for when they can install the firmware, and re-wire the system to get the final integrated solution.
However, after reading the release note, it appears that the way they suggest this all works is different than what my installer had said would occur (and the installer is referencing what they were told by SolarEdge). From what I can tell, is that the PV and battery are on the grid side, and would feed an ATS with the generator. When power goes out, we run on battery, and when the battery gets low, it switches to generator to (as I understand it) power the whole house. I'm not sure if the generator would also charge the battery.
I've mentioned this to the installer, who is going to look into it more.
I must admit, I've gotten a real sour opinion of SolarEdge from the misleading advertising of the firmware availability, and the horrible customer support I've received from them over the year. I'm not happy with my installer, mostly because they haven't stayed on top of things, and have been very unresponsive (their claim is they are flat out with installs due to rate increases lately - my response being that I've already paid in full for the system - which I did so that I could declare everything on 2021 taxes - a mistake I'm now regretting).
It raises two questions.
First, am I understanding the release note and how the system would operate, or is there some other configuration that would be used (like what was mentioned at design time)?
Second, if the generator is to run the whole house, is a 10kWh generator sized correctly (as that was not it's initial intent)?
Hence the subject of this thread.